A welding or additive manufacturing system includes a contact tip assembly having first and second exit orifices. A wire feeder is configured to deliver a first and second wire electrodes through the exit orifices. An arc generation power supply is configured to output a current waveform to the wire electrodes simultaneously, through the contact tip assembly. The current waveform includes a bridging current portion, and a background current portion having a lower current level than the bridging current portion. The bridging current portion has a current level sufficient to form a bridge droplet between the wire electrodes before the bridge droplet is transferred to a molten puddle during a deposition operation. Solid portions of the wire electrodes do not contact each other during the deposition operation. The bridge droplet is transferred to the molten puddle during a short circuit event between the molten puddle and the wire electrodes.

The invention relates to a method for contactless ignition an arc (L) between an electrode (3) and a workpiece (4) which is to be welded, for carrying out a welding process, wherein a welding current (I) and a welding voltage (U) are provided at an output (2) of a welding current source (1), wherein the welding current source (1) contains a resonance converter (5) for generating a periodically varying, preferably substantially sawtooth-shaped, open circuit welding voltage (U.sub.LL) with voltage maxima (U.sub.LL,max) which recur periodically with a repetition rate (f.sub.w) and a welding current source (1) for carrying out the igniting process. In order to achieve reliable contactless ignition of the arc (L) without complicated circuitry, the resonance converter (5) is formed by a series-parallel resonant converter, and temporally synchronous high-frequency pulses (U.sub.I,HF) are superimposed on the open circuit welding voltage (U.sub.LL) in the region of at least some of the periodically recurring voltage maxima (U.sub.LL,max) of the open circuit welding voltage (U.sub.LL).

A welding system includes an engine-driven welder generator that produces welding power. A welding torch receives the welding power and applies it to a stick electrode to initiate and maintain a welding arc. A parameter of the welding power, such as voltage, is monitored, such as to determine whether spikes occur during a short time after arc initiation. Based upon the monitored parameter, the engine speed is controlled. The engine speed may be increased or maintained at an elevated level if the monitored parameter indicates that particular types of electrode are being used, such as XX10 or cellulose electrodes.

A welding system includes an engine-driven welder generator that produces welding power. A welding torch receives the welding power and applies it to a stick electrode to initiate and maintain a welding arc. A parameter of the welding power, such as voltage, is monitored, such as to determine whether spikes occur during a short time after arc initiation. Based upon the monitored parameter, the engine speed is controlled. The engine speed may be increased or maintained at an elevated level if the monitored parameter indicates that particular types of electrode are being used, such as XX10 or cellulose electrodes.

A method and system to weld or join workpieces employing a high intensity energy source to create a weld puddle and at least one resistive filler wire which is heated to at or near its melting temperature and deposited into the weld puddle.

A system and method are disclosed for polishing and lubricating an aluminum welding wire. The system and method draw stock aluminum wire from a spool, subject the stock wire to a plurality of drawing and thermal treatment steps to obtain a wire having a final diameter suitable for use in a continuous welding apparatus. Immediately after the final drawing step, the wire is subjected to a polishing and lubricating process in which a cord that is impregnated with a lubricant is passed over the surface of the wire. The cord serves to remove contaminants, such as metal fines, from the surface of the wire, and also to provide a layer of lubricant over the surface of the wire. The resulting wire has an improved appearance, will not clog the automatic welding apparatus, and the lubricant will not contribute adversely to weld porosity in use.

Methods and apparatus to control hot-start weld current for arc ignition are disclosed. An example welding-type power supply includes a power converter to output welding-type current, a temperature monitor to determine a temperature of an electrode using at least one of a temperature measurement or a thermal model, and a current controller to control a hot-start weld current output by the power converter based on the temperature of the electrode.

Methods and apparatus to control hot-start weld current for arc ignition are disclosed. An example welding-type power supply includes a power converter to output welding-type current, a temperature monitor to determine a temperature of an electrode using at least one of a temperature measurement or a thermal model, and a current controller to control a hot-start weld current output by the power converter based on the temperature of the electrode.

There is provided an arc welding control method for performing a forward/reverse feeding control of alternating a feeding rate of a welding wire between a forward feeding period and a reverse feeding period, and generating short-circuiting periods and arc periods to perform welding. The welding wire is fed forwardly upon starting the welding. The forward feeding is continued during a transient welding period from a time point at which the welding wire comes in contact with a base material and conduction of welding current is started to a time point at which convergence on a steady welding period is performed. The transient welding period is terminated at the short-circuiting period. The forward/reverse feeding control is started from the reverse feeding period after the termination of the transient welding period.

There is provided an arc welding control method for performing a forward/reverse feeding control of alternating a feeding rate of a welding wire between a forward feeding period and a reverse feeding period, and generating short-circuiting periods and arc periods to perform welding. The welding wire is fed forwardly upon starting the welding. The forward feeding is continued during a transient welding period from a time point at which the welding wire comes in contact with a base material and conduction of welding current is started to a time point at which convergence on a steady welding period is performed. The transient welding period is terminated at the short-circuiting period. The forward/reverse feeding control is started from the reverse feeding period after the termination of the transient welding period.